About the project

In an effort to monitor air-quality in the national capital and other cities in India, Hindustan Times brings you a real-time air pollution map.

Indian cities are struggling with a pollution crisis. Delhi, in particular, has consistently recorded the highest levels of air pollution worldwide.

To understand the complexity of the problem, we have fed the data from government sensors and other reliable sources into a centralized, accessible map. With our representation of the data, you can have an easy access to the status of air quality across the country.

The data could point to patterns or trends which could, in turn, inform future reportage by our newsroom. More importantly, we hope this becomes a resource for our audience to track pollution levels in their respective cities.

Note: The data is from Central Pollution Control Board (CPCB), American Embassies and IndiaSpend on a real-time basis. The Hindustan Times shall not be responsible in any manner whatsoever for the correctness and accuracy of the data taken from the above sources.

Johnson Jeba

Tech and IT Team at HT Media.

Explainers

What is PM2.5?

PM stands for Particulate Matter. PM2.5 are fine particles of diameter 2.5 micrometers or less. These particles are invisible to a naked eye and can only be seen by using an electron microscope. They are found in the air, including dust, dirt, soot, smoke, and liquid droplets.

What is PM10?

What is AQI & how is it calculated?

AQI stands for Air Quality Index. It’s an Index to define the air quality which tells us how clean or polluted the air is. There are six AQI categories namely Good, Satisfactory, Moderate, Poor, Very Poor and Severe. The AQI considers eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb). Based on the measured ambient concentrations of these pollutants, a sub-index is calculated for each of these and the worst sub-index reflects the overall AQI.

We calculate AQI based on various pollutant values as per the slabs provided by CPCB on its website. The slabs only calculate the AQI to a maximum of 500. We have linearly extrapolated the last slab (301-400) for all the pollutants to show AQI beyond 500.